Has anyone got an example of Themes working with e4.2.1 + RAP 2.0M3 yet?
Really struggling with this, although have read the "new and noteworthy".
Just trying to use a simple SWT-style helloworld project to begin with, run as RWT, but doesn't seem to matter what I do, the Themes defined in Extensions don't get applied.
Could do with an example project, or step-by-step tutorial to show how to set it up...
It is quite possible I am totally misunderstanding how to use Themes/CSS with RWT/RAP, as I am new to it (not migrating from previous release of Eclipse or RAP).

I'm probably missing something simple here, perhaps a startup parameter, or something with the servlet path, but don't understand what is happening enough to work it out. I'm concerned it might simply be a bug in RAP 2.0M3 too...?

Hi Joh,
if you are using extension points you must run your application as "RAP
Application". In case of "RWT standalone" or plain OSGi application you
have to configure your application with the new Application
Configuration API [1]. See [2] for different setups possible with RAP.

The RunAs Configuration uses web.xml from my WEB-INF/lib folder and specifies a Servlet Path of 'rapier'. The application starts up and runs just fine, but without the CSS styling applied anywhere.

Perhaps my expectations are incorrect here and I'm not launching it correctly, but I'm just not understanding whether I've specified the theme usage correctly. Should I be specifying the theme somehow at launch time, or in the Application Configuration java... or something else?

Thanks again Ivan, that solution makes sense. Feel like I'm almost there now...

However, for some reason it cannot access the CSS file as a resource, which is included in the binary of the project. Here is the runtime error:

2012-11-30 11:21:08.468:INFO:oejs.Server:jetty-8.1.3.v20120522
2012-11-30 11:21:08.631:INFO:oejw.StandardDescriptorProcessor:NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet
2012-11-30 11:21:08.691:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/C:/JVM/Eclipse421/workspace/.metadata/.plugins/org.eclipse.rap.ui.launch.rwt/RWT%20from%20web.xml/web-app/},C:\JVM\Eclipse421\workspace\.metadata\.plugins\org.eclipse.rap.ui.launch.rwt\RWT from web.xml\web-app
2012-11-30 11:21:08.691:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/C:/JVM/Eclipse421/workspace/.metadata/.plugins/org.eclipse.rap.ui.launch.rwt/RWT%20from%20web.xml/web-app/},C:\JVM\Eclipse421\workspace\.metadata\.plugins\org.eclipse.rap.ui.launch.rwt\RWT from web.xml\web-app
2012-11-30 11:21:08.988:WARN:oejw.WebAppContext:Failed startup of context o.e.j.w.WebAppContext{/,file:/C:/JVM/Eclipse421/workspace/.metadata/.plugins/org.eclipse.rap.ui.launch.rwt/RWT%20from%20web.xml/web-app/},C:\JVM\Eclipse421\workspace\.metadata\.plugins\org.eclipse.rap.ui.launch.rwt\RWT from web.xml\web-app
java.lang.IllegalArgumentException: Could not open resource css/aqua.css
at org.eclipse.rap.rwt.internal.theme.css.CssFileReader.readStyleSheet(CssFileReader.java:52)
at org.eclipse.rap.rwt.internal.application.ApplicationImpl.readStyleSheet(ApplicationImpl.java:159)
at org.eclipse.rap.rwt.internal.application.ApplicationImpl.addStyleSheet(ApplicationImpl.java:123)
at org.eclipse.rap.rwt.internal.application.ApplicationImpl.addStyleSheet(ApplicationImpl.java:115)
at iet.rap.launcher.RapierConfiguration.configure(RapierConfiguration.java:14)
...

Is this whole Theme business registered and applied programmatically now, or do I need to register it in Extensions/ExPoints? I'm assuming the whole thing is programmatic (i.e. in my ApplicationConfiguration implementation class)? This looks like this now:

I've even tried referencing the CSS file as an absolute path on my workstation, but that didn't work.

It is almost like it is insisting that the CSS file is somehow included as a special resource, and I need to register it via a resource loader, and goodness knows what.
Unfortunately I'm not offay enough was RAP to understand what it is trying to do under the covers, so it is hard to guess what to try next.

Is there a possibility that there is actually a problem with CSS themes in RAP 2.0M3? Could someone actually create an example (I'm using Eclipse 4.2.1 remember), and post it as reference to show it working please?

Hold the press!
Got it working... the problem was the location of the CSS files... I assumed that the resources should be loaded relative to the project root, but in fact it was relative to the source root. Moving the CSS folder alongside my 'SRC' source folder was enough for it to start working (hopefully the image will display ok...):